In this science experiment we will make soft shell eggs. Soaking the eggs in vinegar creates a chemical reaction involving carbon dioxide gas. This reaction dissolves the hard outside calcium carbonate shell leaving only the soft inner membrane of the egg that holds the yolk.
1 egg Vinegar Clear jar or glass with lid
Process Soft Shell Egg Experiment: 1. Place the egg into the jar.
2. Fill the jar with vinegar. 3. Poke a small hole in the lid of the jar with a nail and hammer.
4. Screw the lid on.
5. Record your observations of how the egg looked when you placed into the vinegar at the start. How does it look and feel?
6. Let the egg sit a couple days until the calcium carbonate shell is completely dissolved. Record more notes on what you see over the course of these next few days.
7. Once the egg hard outside shell is totally dissolved away, pour out the vinegar and remove the egg. How does it look and feel now?
The Science Behind Soft Shell Egg Experiment: Eggs contain something called "calcium carbonate."This is what makes them hard. Vinegar is an acid known as acetic acid. When calcium carbonate (the egg) and acetic acid (the vinegar) combine, a chemical reaction takes place and carbon dioxide (a gas) is released. This is what the bubbles are made of. The chemical reaction keeps happening until all of the carbon in the egg is used up -- it takes about a day. When you take the egg out of the vinegar it's soft because all of the carbon floated out of the egg in those little bubbles.
NOW TRY THIS: Leave the same egg sitting out on the table for another day. Now feel it again. It's hard! The calcium left in the egg shell stole the carbon back from the carbon dioxide that's in the air we breath. - OR - If you were using a raw egg, once the shell has softened, you can place the egg in water and it'll absorb and expand via osmosis until the shell finally bursts.
Extra Credit: Rubber Chicken Bone What makes our bones hard? That's right! Calcium carbonate -- the same thing that made the egg shells hard. Take some thin chicken bones and drop them in vinegar for a day. Take them out and they'll be soft just like the egg shells were. Now you can tie them in a knot, just like a piece of string. Leave them sitting out on the table and they'll get hard again! Take them to school for sharing time and see if your classmates can figure out how you did it!
Now grab your friends and try the Soft Shell Egg Experiment.
You can also try the Folding Egg experiment for more fun!